1. Field of the Invention
This invention relates to apparatus for testing the combustion of a fuel and to a method of testing the combustion of a fuel. Such testing is required, for example, when designing a burner or determining appropriate conditions for combustion of a particular fuel, especially in the field of gas turbines.
2. Brief Description of the Related Art
Thermoacoustic pulsations may limit the range of operating conditions where a modern gas turbine can operate with low emission and high efficiency performance. These pulsations are caused by complex interaction between hydrodynamic instabilities, unsteady heat release, and the acoustic field. Because of its complex nature, this phenomenon is very difficult to model or simulate accurately. Therefore, tests in a combustion test facility remain the most important tool to assess thermoacoustic behaviour of a combustion system. It is of crucial importance that the acoustic boundary conditions of the test rig are very similar to the acoustic behaviour of the gas turbine combustion chamber. The acoustic boundary conditions (or acoustic impedance) of a test facility can be changed by modifying the geometry of the test rig. However, such hardware changes are expensive and time consuming.
What is desired is apparatus which enables the acoustic boundary conditions to be modified without changing the geometry of the test rig.